Metacharacters

The following characters have special meaning in search patterns:

Character Meaning
. Match any single character except newline.
*

Match any number (or none) of the single character that immediately precedes it. The preceding character also can be a regular expression (e.g., since . (dot) means any character, .* means match any number of any character—except newlines).

^

Match the beginning of the line or string.

$

Match the end of the line or string.

[ ]

Match any one of the enclosed characters. A hyphen (-) indicates a range of consecutive characters. A circumflex (^) as the first character in the brackets reverses the sense: it matches any one character not in the list. A hyphen or close bracket (]) as the first character is treated as a member of the list. All other metacharacters are treated as members of the list.

[^ ]

Match anything except enclosed characters.

\{ n,m \}

Match a range of occurrences of the single character that immediately precedes it. The preceding character also can be a regular expression. \{n\} matches exactly n occurrences, \{n,\} matches at least n occurrences, and \{n,m\} matches any number of occurrences between n and m.

{ n,m }

Like \{ n,m \}. Available in grep by default and in gawk with the -Wre-interval option.

\

Turn off the special meaning of the character that follows.

\(\)

Save the matched text enclosed between \( and \) in a special holding space. Up to nine patterns can be saved on a single ...

Get Linux in a Nutshell, Third Edition now with the O’Reilly learning platform.

O’Reilly members experience books, live events, courses curated by job role, and more from O’Reilly and nearly 200 top publishers.